3D inversion of QMAGT airborne magnetic gradiometry data for susceptibility and magnetization vector models of the Thompson Nickel Belt in Manitoba, Canada

Abstract

Following recent advances in SQUID technology, full tensor magnetic gradiometry (FTMG) is emerging as a practical exploration method. We introduce 3D regularized focusing inversion based on the Gramian regularization and moving sensitivity domain to interpret the FTMG data efficiently. A helicopter-borne QMAGT full tensor magnetic gradiometry (FTMG) survey was conducted over the Thompson Nickel Belt by Dias Airborne contracted by Vale Canada LTD. This project aimed to study the location and structure of the P2 member sulfidic meta sedimentary rocks of the Paleoproterozoic Ospwagan Group hosting the Mystery ultramafic intrusion and the associated Ni sulfide mineralization proximal to the survey area. The observed FTMG and calculated total magnetic intensity (TMI) data were analyzed and inverted separately using the developed 3D inversion methods. The data were inverted for susceptibility and magnetization vector models. This is one of the first papers to present the applied inversion of FTMG data towards a magnetization vector model. We also present a comparison of the inversions using the FTMG data and the calculated TMI data.